Conveyer system control



Oct. 29, 1946.

CONVEYER SYSTEM CONTROL Filed Nov. 16, 1944 2 Sheets-Sheet l INVENTOR. GERALD DEAKIN Oct. 29, 1946. I DEAKN 'I 2,410,05l

7 CONVEYER SYSTEM CONTROL Filed Nov. 16, 1944 2 Sheets-Sheet 2 INVENTOR.

GERALD DEAKIN ATTORN Y Patented Oct. 29, 1946 CONVEYER SYSTEM CONTROL Gerald Deakin, New York, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application November 16, 1944, Serial No. 563, 756

(Cl. 214-60 i 16 Claims. 1

The present invention relates to a control for a conveyer system and particularly to a control for a conveyer system in which individual units of the conveyer are arranged to automatically discharge their load at predetermined receiving Stations.

More particularly still the invention relates to a control circuit so arranged that the major ele ments of the control are mounted in stationary positions at the various receiving Stations and only a small portion of the control apparatus is carried by the individual moving units of the con veyer.

It is an object of the invention to provide a conveyer system of the automatic discharging type having a control, the major elements of which are located at the receiving Stations.

It is another object of the invention to provide such a control system as that mentioned in which each unit of the conveyer can-les settable devices and minor circuit elements whereby the unit may be conditioned for discharging its load at any one of a plurality of receiving Stations;

Other objects and features of the invention will appear when the following description is considered in connection with the annexed drawings in whichi Figure 1 is an end elevationof aconveyer unit of a type to which my invention is applicable;

Figure 2 is a front elevation of the conveyer unit of Figure 1; e e i i Figure 3 is a View similar to Figure 1 but show ing the equipment in its discharging position after operation bythe circuit of the present inven ti-on; i

Figure 4 is a front elevation of the unit in the position illustrated in Figura 3;

Figura 5 is a schematic wiring diagram of the portion of the control circuit located on each conyer unit; and i a Figure 6 is a schematic wiring diagram of the portion of the control circuit located at each re ceiving station. i i i i Referring now toFigures l through 4 which illustrate a preferred form of conveyer system to which my control may be applied, it will be seen that the conveyer comprises a pair of.tracks I which are Suspended adjacent each other by means of a bracket 2, or any other suitable sup port, which bracket is in turn afiixed to an overhead surface as, for example, the ceiling 3 of the room.` Obviously, the tracks `-may be supported in any other suitable manner and at any convenient height. Each conyeyer unit` comprises the hangers 4 which dependfrcm theshaftsj carrying rollers 5 which run on` the tracks I. The various units of the conveyer are attached to a cable 'l at spaced intervals therealong, the cable being driven in any well known and suitable man ner.

The hangers 4 are formed at their lower ends to provide pivot points for pins 8 which pins are fixed to and extend from platform 9 on which the goods are placed, normally manually.

In accordance with my invention I provide on each conveyer unit a plurality of keys !0 (Figures 2, 4 and 5) together .with a potentiometer I l (Figure 5) and three contact brushes !2, l3 and !4 (Figures 1, 3 and 5).

At each receiving station I provide a contact unit comprising the three segmental contacts !5, !6 and l'l together with the circuit illustrated in Figure 6 and including the magnet or solenoid IS. The magnet |8 is provided with an armature !9 which is adapted to operate against the rod and thereby oscillate the arms 2l of the unit counterclockwise about their pivot points 22 thereby causing the unit to discharge its ,load by virtue of the inclination of the platform 9, as il lustrated particularly in Figures 3 and 4.

As has been indicated, the circuit elements provided onfeach conveyer unit comprise the poten tiometer l l which is tapped at various points and -to which connection can be made by operation of the keys IO. Current is :fed to the potentiometer through the brushes l2 and l4 and the potential existing at the brush !3 isdetermined in accordance with` the operation of the keys ID These keys ll] are preferably looking keys which will retain their closed position when set until released, either manually or automaticallyas the case may be. At each receiving station in addition to the contact segments !5, !6 and I'l there is provided acircuitincluding the rectifiers 23, 24 and 25, electron tube 26, potentioneter 21 and `resistance 28. The rectier units of the rectifiers 23, 24 and 25 are poled so that current will flow from positive to negative in the direction of the arrows. The filament 29 of tube 26 is heated by virtue of current supplied from a suitable source, shown in this instance as an A. C. source, through the transformer 30. A D. C. source could of course be used if desired. i i

The details of the` circuit are best described by reference to the operation of the system. In settng up the system each receiving station is adjusted so that it will be rendered operative when a conveyer unit closes circuits through the contacts !5, IG and l'l. and brushes l2, l3 and !4 when a particular key n has been operated. This adjustment involves merely the setting of the var.. iable contact'3l of potentiometer 21 to a position corresponding to the tap point which is connected by operation of the particular key [G considered.

Let it be first assumed that the conveyer unit under consideration is travelling between receiving Stations and that, therefore, no circuits are completed through the contacts l'5, s and IT and the brushes [2, !3 and !4, respectively. Under these conditions, current fiows normally from the positive to negative terminal of rectifier` unit 23 over one circuit including conductor 32 and potentiometer 21 and over another circuit including conductor 33, resistance 28, ccnductor 34, rec tifier unit 25, conductor 35 to variable tap 3| and part of potentiometer 27 to the negative terminal of rectifier unit 23. The righthand side of rectifier unit 25 is thus made positive and the left side negative and current flows through two par allel paths, one including rectifiers 31 and 33 and the other rectiers 39 and 38. Since rectifier 31 is positively polarized and rectifier 36 negatively po larized, the former has a low impedance and the latter a high impedance. Likewise, since recti fier 39 is negatively polarized and rectifier 38 positively. polarized, the former has a high impedance and the latter a low impedance. Thus filament or cathode 29 of tube 25 is made positive withrespect to grid 40 and no or a very small current fiows from the cathode' 29 to plate 41. It will be seen that the left side of rectifier 25 will be weakly or strongly negative according to the position of tap 3! on potentiometer 21.

Now if the unit arrives at a receiving station other than the one selected, a circuit will be ,completed which will apply positive potential over conductors 33 and 4! and through contact I and brush l2 to the upper terminal of potentiometer Il. Likewise, a circuit will be completed from the negative side of rectifier 23 over conductor 42 and contact l'l and brush [4 to the lower side of potentiometer H. In 'addition, a circuit will be completed from the righthand' end of the rectifier unit 25 over conductors 34 and 43, contact 16, brush !3 and conductors 44 and 45 to any operated key w, and thence through that key to thecorresponding tap point'on po tentiometer H. since the setting of the key does not correspondcwith the setting of 'variable contact 31 of potentiometer 21, there will be a difference of potential existing at the right and left ends of the rectifierunit 25. This difference in potential will operate in the manner described above in connection with the circuit through resistance 28 to provide a negative bias on' tube 4 0 and 'this tubewill continue to be non-conducting. If, for example, the potential existing on conductor 44, 45 brush !3, contact Hi, conductor 43 and therefore, at the righthandend of the ,rectifier unit .25 is more positive than tht'existing oncontact 3 and at the lefthand enclof rectifier 25, then due to the low impedarce of rectifier 3? .to current flow in't'hat direction and' the high impedance of rectifier 36 a relatively high positive potential will exist on the cathode 29 of tube 26. Likewise, because of the high impedance of rectifier 39 'and the low impedance Vof'rectifier 33 a relatively high negative potential will exist on' grid `4!) of the tube. It should be 'understood that in this event although the bias- 'ing resistance 28' is still incircuit, it is now sub- `startially in parallel With the circuit through the potentiometer Il and consequently the bias sup- 'plied by it is negligible.

'- When the conveyer unit under con ideration reaches the receiving station adjusted to correspond to the key operated upon the unit, the k potential applied to the right and lefthand ends of rectifier unit 25 over the circuits previously described is substantially equal. consequently the negative bias is removed from the grid 40 of tube 26 and current then fiows through the circuit comprising rectifier 24, conductor 46, the two legs of filament 29 in parallel as a cathode, plate 4?, conductor 48, magnet [8 and conductor 49. Operationof magnet !8, as has been described, causes operation of bar or roller 20 and elevation of the arms 21 so that these arms unlatch from the latching bars of the conveyer unit and permit the platform 9 to drop into the position shown in Figure 3 thereby discharging the load at the selected receiving station.

As has been stated hereinabove, platform 9 may be restored manually by the operator at the receiving station Or may be automatically restored. such automatic restoration can be effected by the use of a cam 50 (Figures 1 through-4) and a bracket such as 51 (Figure l). It will be seen that when the carrier or conveyer unit in its traverse reaches a bracket such as 55, the camming surface 50 rides up on the bracket andre- ,stores the platform to its horizontal position causing the arms 2! to latch behind the latching bars.

The keys o may either be reset by the receiving station operator or may be automatically While I have described a preferred'embodir'r'ent of my invention, many different forms thereof may be utilized and, therefore, I wish to be limited not by the foregoing description but solely by the appended claims.

What is claimed is:

I 1. In a control circuit for causing the unloading of a conveyer at any one of a plurality of points on its traverse, in combination' a tapped potentiometer on the conveyer, settable means forselectingone of said taps a variable potentiometer at'each unloadingpoint means for adjustingsaid' last mentioedpotentiometer to cor respond with the'setting of any one'of said settable means, means at eachunloading point to supply an Operating voltage tlsaidpotentiometers in parallel, an impedance unit comprising two'parallel'branch "circuits each including two 55 oppositely poled uni-directional impedances-in series, the impedances of one branch being reversely poled withrespect to correspcnding impedances in the other branch, whereby current flow in either direction through said unit causes the common terminal of the two impedances in one branch to have a'relatively higher positive potential than the corresponding point in 'the other branch, means connecting oneterminal of said impedance unit to the tap-point on said conveyer potentiometer, and means connecting the other terminal of said' impedance unit to the un'- loading point potentiometer whereby when the potentiometers are similarly adjusted no current flows and the two common connections between impedances in the branches of theimpdance unit are atthe same potential. i e

2. In a control circuit for causing the unloading of a conveyer at any one of'a plurality of points on its tr avers,-"in combination: a poten- 75 timeter' on *the eonve erg a plurality of taps on said potentiometer, settable means for selectin one of said taps, a potentiometer at each unloading point, a variable contact on each said potentiometer; an impedance unit comprising two parallel branch circuits each including two oppositely poled unidirectional impedances, the impedances of one branch being reversely poled with respect to those in the other branch, whereby current flow in either direction through said unit causes the common terminal of the two impedances in one branch to have a relatively positive potential with respect to the corresponding point in the other branch, means to supply an operating Voltage to said unloading point potentiometers, commutator means for supplying the same Operating voltage to said conveyer potentiometers when the conveyer is at an unloading point, commutator means for supplying the potential from a selected tap point on said conveyer potentiom-` eter to one terminal of said impedance unit, and means for supplying the potential from the varia ble contact of said unloading point potentiometer to the other terminal of said impedance unit.

3. In a control circuit for causing the unloading of a conveyer at any one of a plurality of points on its traverse, in combination, a potentiometer on the' conveyer, a plurality of taps on said potentiometer, settable means for 'selecting one of 'said taps, a potentiometer at each unloading point, a variable contact `or each said potenti ometer, an impedance unit comprising two par allel branch circuits each including two oppositely poled unidirectional'impedances, the im pedances of one branch being reversely poled with respect to those in the other branch, whereby current flow in either direction through said unit causes the common terminal of the two impedances in one branch to have a relatively positive potential with respect to the corresponding point in the other branch, means to supply an Operating voltage to 'said unloading point potentiometers, commutator means for supplying the same 'Operating voltage to said conveyer potentiometer when the conveyer is at an unloading point, commutator means for supplying the potential from a selected tap point on said conveyer potentiometer to one terminal of said impedance unit; means for supplying the potential from the variable contact of said unloading point potentiometer to the' other terminal of said impedance r unit, and potential responsive means connected across the common terminals of the two im'- pedances of one branch circuit of said impedance unit and the common terminal of the two impedances in the other branch of said impedance unit, whereby when the unloading point potentiometer and the conveyer potentiomter are similarly set no current flows through the impedance unit and'the potential responsive device is operated. i i i 4. In a control circuit for causing the unloading 'of a conveyer at any one of a plurality of points on its traverse, in combination, an impedance unit at each unloading point, each unit comprising two parallel branch circuits, each including two 01:- positely poled unidireetional impedances, the impedance's of one branch being reverselypoled with respect to those in the other branch, whereby current flow in either direction through said unit causes the common terminal of two impedances in one branch to be at a relatively higher positive potential than the corresponding point in the other branch, means for normally causing current flow through said impedance unit, and a potential' responsive device connected across the `responsive device.

5. In a control circuit for causing the unloading of a conveyer at any one of a pluralityof points on its traverse, in combination, an impedance unit at each unloading point, each unit comprising two parallel branch circuits, each including two oppositely poled unidirectional impedances, the impedances of one branch being reversely poled with respect to those in the other branch, whereby cur-` rent flow in either direction through said unit causes the common terminal of two impedances in one branch to be at a relatively higher positive potential than the corresponding point in the other branch, means for normally causing'current flow through said impedance unit, a triode having its grid-filament circuit connected across the common impedance terminals of the two branches, said triode being normally biased to inoperative condition, means operable upon the conveyer reaching a selected unloading point to cause cessation of current flow through said impedance unit and operation of said triode, and magnetic means in the plate circuit of said triode for Operating said conveyer to unloading position.

6. In a control circuit for causing the 'unloading of a conveyer at any one of a plurality of points on its traverse, in combination, animpedance unit at each unloading point, each unit comprising two parallel branch circuits, each including two oppositely poled unidirectional impedances, the impedances of one branch being reversely poled with respect to those in the other branch, whereby current flow in either direction through said unit causes the common terminal of the two impedances in one branch to be at a relatively higher positive potential than the corresponding point in the other branch, means for normally causing current flow through said impedance unit, a potentiometer on said conveyer, taps on said potentiometer, settable means for selecting one of said taps, a potentiometer at each unloading station, a'variable contact on each unloading station potentiometer, means for applying an Operating potential to said unloading 'station potentometers, commutator means for applying said operating potential to the conveyer potentiometers, means connecting the variable contact of each unloading station sp-otentiometer to one terminal of said impedance unit, commutator means for onnecting the selected tap of the conveyer potentiometer to the other terminal of said impedance unit when said` conveyer reaches any un-` loading station, and a triode having its grid filament circuit connected across the'common impedance terminals of the two branches, 'said tri ode being normally biased to inoperative condition, means operable upon the conveyer reaching a non-selected unloading point to apply a higher potential to oneterminal of said impedance unit than to the other and continue the biasupon the triode; and means operable upon the conveyer reaching a selected unloading station to appl y equal potentials to the terminals of the impedance unit to remove the bias from said triode.

7. In a control circuit for causing the unloading of a conveyer at any one of a plurality of points on its traverse, in combination, an imped ance unit at each unloading point, each unit comprising two parallel branch crcuit's, each includwhen the current flows in one direction than when the current flows in the other direction, said parallel branch circuits being reversely connected whereby the two central points have their voltages changed by difierent amounts when there is a change in the rate of current flow.

14. In a control system for a conveyer of the type wherein there are a number of stations at which materials from the conveyer may be unloaded and it is desirable to select the station for the unloading of each unit of material prior to the arrival of the unit of material to the station, the combination of, a plurality of stationary circuit assemblies corresponding in number to the unloading stations and each having contactor means positioned at its respective station, and a plurality of movable units each adapted upon energization to produce a distinctive output potential said movable units being mounted respectively to move with the various units of material and having movable contactor means positioned respectively to engage the various contactor means at the respective unloading Stations, each of said stationary circuit assemblies including means constituting a, source of potential which is supplied to the various movable units through said contactor means as the various movable units are positioned at the respective unloading Stations, each of said stationary circuit assemblies also including an impedance assembly and a stationary unit connected to the source of potential and having an output potential circuit connectable through said impedance assembly and said contactor means to the output potential of each of the movable units, said impedance assembly comprising two parallel circuits each formed by a pair of impedance units the impedance of each of which is greater when the current fiows in one direction than when fiowing in the other direction with the impedance units of each parallel circuit being reversely.coupled at a common terminal whereby for any given value of current flow the potential of the common terminal is different when the current is fiowing in one direction from what it would be if the current were fiowing in the opposite direction, said parallel circuits being reversely connected where-' by the two common terminals have opposite potential variations with any given change in current flow, whereby current flow through said impedance assembly produces a potential bias between said common terminals which potential bias is in the same direction regardless of the direction of flow of current through said parallel circuits, and each of said stationary assemblies also including means responsive to the existence of a zero potential bias between said common terminals to identify the arrival of the units of material to be unloaded at that particular station. e

15. In a conveyer system of the type Wherein there are a number of stations at which materials may be unloaded and signal means is provided on the conveyer to move with each unit of material to produce a distinctive voltage indicating that that particular unit of material is to be unloaded at a particular station and wherein each station is provided with means to produce a distinctive potential, an impedance means positioned at a station and adapted to be connected between the potential produced by the signal means on the conveyer and the potential produced at the station, said impedance means comprising two parallel branch circuits each formed by two op-. positely poled unid irectional impedances with one branch circuit being reversely poled with respect to the other branch circuit, whereby a current flow through the circuits in either direction causes the common terminal of the two impedances in one branch circuit to be at a relatively higher positive potential than the corresponding point in the other branch circuit.

16. Apparatus as described in claim 15 which includes, an electronic device having a controlled circuit and a control grid which control grid is connected to be biased by the potential difierence existing between said common terminals thereby to prevent the flow of current through the controlled circuit, and means responsive to the flow of current through said controlled circuit to unload the conveyer.

GERALD DEAKIN. 

